var left11=document.getElementsByClassName("left11")[0];
var center=document.getElementsByClassName("center")[0];
var left12=document.getElementsByClassName("left12")[0];
var center1=document.getElementsByClassName("center1")[0];
var left13=document.getElementsByClassName("left13")[0];
var center2=document.getElementsByClassName("center2")[0];
var right11=document.getElementsByClassName("right11")[0];
var center3=document.getElementsByClassName("center3")[0];
var right12=document.getElementsByClassName("right12")[0];
var center4=document.getElementsByClassName("center4")[0];
var right13=document.getElementsByClassName("right13")[0];
var center5=document.getElementsByClassName("center5")[0];
var finish=document.getElementsByClassName("submit")[0];

left11.onclick=function()
{
    center.style.display="block";
}
left12.onclick=function()
{
    center1.style.display="block";
}

left13.onclick=function()
{
    center2.style.display="block";
}
right11.onclick=function()
{
    center3.style.display="block";
}
right12.onclick=function()
{
    center4.style.display="block";
}

right13.onclick=function()
{
    center5.style.display="block";
}
finish.onclick=function()
{
    center.style.display="none";
}
